title: A 2-hour diagnostic protocol for possible cardiac chest pain in the emergency department: a randomized clinical trial.
abstract: OBJECTIVE
  Patients with chest pain represent a high health care burden, but it may be possible to identify a patient group with a low short-term risk of adverse cardiac events who are suitable for early discharge.
  
  
  OBJECTIVE
  To compare the effectiveness of a rapid diagnostic pathway with a standard-care diagnostic pathway for the assessment of patients with possible cardiac chest pain in a usual clinical practice setting.
  
  
  METHODS
  A single-center, randomized parallel-group trial with blinded outcome assessments was conducted in an academic general and tertiary hospital. Participants included adults with acute chest pain consistent with acute coronary syndrome for whom the attending physician planned further observation and troponin testing. Patient recruitment occurred from October 11, 2010, to July 4, 2012, with a 30-day follow-up.
  
  
  METHODS
  An experimental pathway using an accelerated diagnostic protocol (Thrombolysis in Myocardial Infarction score, 0; electrocardiography; and 0- and 2-hour troponin tests) or a standard-care pathway (troponin test on arrival at hospital, prolonged observation, and a second troponin test 6-12 hours after onset of pain) serving as the control.
  
  
  METHODS
  Discharge from the hospital within 6 hours without a major adverse cardiac event occurring within 30 days.
  
  
  RESULTS
  Fifty-two of 270 patients in the experimental group were successfully discharged within 6 hours compared with 30 of 272 patients in the control group (19.3% vs 11.0%; odds ratio, 1.92; 95% CI, 1.18-3.13; P = .008). It required 20 hours to discharge the same proportion of patients from the control group as achieved in the experimental group within 6 hours. In the experimental group, 35 additional patients (12.9%) were classified as low risk but admitted to an inpatient ward for cardiac investigation. None of the 35 patients received a diagnosis of acute coronary syndrome after inpatient evaluation.
  
  
  CONCLUSIONS
  Using the accelerated diagnostic protocol in the experimental pathway almost doubled the proportion of patients with chest pain discharged early. Clinicians could discharge approximately 1 of 5 patients with chest pain to outpatient follow-up monitoring in less than 6 hours. This diagnostic strategy could be easily replicated in other centers because no extra resources are required.
  
  
  BACKGROUND
  anzctr.org.au Identifier: ACTRN12610000766011.
authors.affiliation: Emergency Department, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Martin
authors.initials: M
authors.lastname: Than
authors.affiliation: Emergency Department, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Sally
authors.initials: S
authors.lastname: Aldous
authors.affiliation: University of Sydney, Sydney, Australia.
authors.forename: Sarah Jane
authors.initials: SJ
authors.lastname: Lord
authors.affiliation: University of Sheffield and Northern General Hospital, Sheffield, England.
authors.forename: Stephen
authors.initials: S
authors.lastname: Goodacre
authors.affiliation: University of Otago, Christchurch, New Zealand.
authors.forename: Christopher M A
authors.initials: CM
authors.lastname: Frampton
authors.affiliation: University of Otago, Christchurch, New Zealand.
authors.forename: Richard
authors.initials: R
authors.lastname: Troughton
authors.affiliation: Emergency Department, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Peter
authors.initials: P
authors.lastname: George
authors.affiliation: Canterbury Health Laboratories, Christchurch, New Zealand.
authors.forename: Christopher Michael
authors.initials: CM
authors.lastname: Florkowski
authors.affiliation: University of Otago, Christchurch, New Zealand.
authors.forename: Michael
authors.initials: M
authors.lastname: Ardagh
authors.affiliation: Emergency Department, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: David
authors.initials: D
authors.lastname: Smyth
authors.affiliation: Emergency Department, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: David Lewis
authors.initials: DL
authors.lastname: Jardine
authors.affiliation: Baylor College of Medicine, Houston, Texas.
authors.forename: William Frank
authors.initials: WF
authors.lastname: Peacock
authors.affiliation: Emergency Department, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Joanna
authors.initials: J
authors.lastname: Young
authors.affiliation: Canterbury District Health Board, Christchurch, New Zealand.
authors.forename: Gregory
authors.initials: G
authors.lastname: Hamilton
authors.affiliation: Canterbury District Health Board, Christchurch, New Zealand.
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Deely
authors.affiliation: Royal Brisbane and Women's Hospital, Herston, and Queensland University of Technology, Brisbane, Australia.
authors.forename: Louise
authors.initials: L
authors.lastname: Cullen
authors.affiliation: University of Otago, Christchurch, New Zealand.
authors.forename: A Mark
authors.initials: AM
authors.lastname: Richards
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications / Q000175:diagnosis*; D000368:Aged; D000789:Angina, Unstable / Q000150:complications / Q000175:diagnosis*; D002637:Chest Pain / Q000175:diagnosis* / Q000209:etiology; D002985:Clinical Protocols; D004562:Electrocardiography; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge; D018570:Risk Assessment; D013997:Time Factors; D019210:Troponin I / Q000097:blood
chemical_list: D019210:Troponin I